Find out what causes cystitis and what can increase your chances of getting the condition.

Cystitis is usually caused by a bacterial infection, although it sometimes happens when the bladder is irritated or damaged for another reason.

Bacterial infections

Most infections are thought to occur when bacteria that live harmlessly in the bowel or on the skin get into the bladder through the urethra (tube that carries urine out of your body) and start to multiply.

Cystitis is much more common in women than men, probably because the anus (back passage) is closer to the urethra in women and the urethra is much shorter.

It's not always obvious how the bacteria get into the bladder, but it can be caused by:

having sex

wiping your bottom after going to the toilet – particularly if you wipe from back to front

inserting a tampon or urinary catheter (a thin tube inserted into the urethra to drain the bladder)